Gauff sets up China Open semi-final with Swiatek, top seed Sabalenka out
The pair have met on eight occasions, and although Swiatek has won seven of these, Gauff did come out on top in their last meeting, in the Cincinnati semi-final.
"It's going to be a tough match. We had a tough match in Cincinnati but I'm really excited and focused to play tomorrow," Gauff said.
Gauff, who won her first Grand Slam title at this year's US Open, needed just one hour and 20 minutes to see off Sakkari, without once losing serve against the fourth-seeded Greek.
"I think I served well on the pressure points, and yeah, I think every match has got better for me in this tournament," Gauff added.
The American, number three in the world, will now face world number two Swiatek in Saturday's semi-final after the Pole battled back from a set down to beat Caroline Garcia 6-7(8), 7-6(5), 6-1.
"For sure it was really intense," Swiatek said.
"We played really fast. There was no time sometimes to think or analyse. I'm happy I used my intuition a lot."
After Garcia won the first set following a tie-break, Swiatek came to within two points of losing the quarter-final in straight sets but came back to force another tie-break.
Swiatek came out on top and in the third set she broke Garcia's serve three times to finish off in style.
"In both of the first sets, every ball counted. I'm happy that in the third I could just go for it," Swiatek added.
World number one Aryna Sabalenka failed to reach the semi-finals as she lost 7-5, 6-2 to fifth seed Elena Rybakina.
Rybakina served 12 aces compared to Sabalenka's four and broke the top seed's serve four times.
"I served really well, so I'm really happy with my performance today," Rybakina said.
After an evenly contested opening set, Rybakina won five consecutive games in the second set.
Rybakina, who lost this year's Australian Open final to Sabalenka, will face Liudmila Samsonova in the semi-final on Saturday after the unseeded Russian defeated 13th seed Jelena Ostapenko 6-3, 6-2.
Samsonova has won all three previous meetings with Rybakina.